Fix wifi-temp: localhost → 127.0.0.1 + install improvements
- wifi-temp: localhost → 127.0.0.1 (RCI blocked after CVE-2026-42533/NDM-4566)
- saveWifiTempPoint: skip null values
- parseWifiTempHistory: skip bad entries, frontend guard
- install.sh: added wget to package deps
- install.sh: added armv5tel to arch detection
- install.sh: rewrite 30-cgi.conf (robust, no fragile sed)
- go.cgi: added armv5tel arch